Skip to main content
eScholarship
Open Access Publications from the University of California

A viral resistance gene from common bean functions across plant families and is up-regulated in a non-virus-specific manner.

  • Author(s): Seo, Young-Su
  • Rojas, Maria R
  • Lee, Jung-Youn
  • Lee, Sang-Won
  • Jeon, Jong-Seong
  • Ronald, Pamela
  • Lucas, William J
  • Gilbertson, Robert L
  • et al.
Abstract

Genes involved in a viral resistance response in common bean (Phaseolus vulgaris cv. Othello) were identified by inoculating a geminivirus reporter (Bean dwarf mosaic virus expressing the green fluorescent protein), extracting RNA from tissue undergoing the defense response, and amplifying sequences with degenerate R gene primers. One such gene (a TIR-NBS-LRR gene, RT4-4) was selected for functional analysis in which transgenic Nicotiana benthamiana were generated and screened for resistance to a range of viruses. This analysis revealed that RT4-4 did not confer resistance to the reporter geminivirus; however, it did activate a resistance-related response (systemic necrosis) to seven strains of Cucumber mosaic virus (CMV) from pepper or tomato, but not to a CMV strain from common bean. Of these eight CMV strains, only the strain from common bean systemically infected common bean cv. Othello. Additional evidence that RT4-4 is a CMV R gene came from the detection of resistance response markers in CMV-challenged leaves of RT4-4 transgenic plants, and the identification of the CMV 2a gene product as the elicitor of the necrosis response. These findings indicate that RT4-4 functions across two plant families and is up-regulated in a non-virus-specific manner. This experimental approach holds promise for providing insights into the mechanisms by which plants activate resistance responses against pathogens.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View